U.S. patent application number 14/365366 was filed with the patent office on 2014-12-25 for process and apparatus for manufacturing tyres for vehicle wheels.
This patent application is currently assigned to PIRELLI TYRE S.P.A.. The applicant listed for this patent is PIRELLI TYRE S.P.A.. Invention is credited to Michele Ballabio, Christian De Col, Maurizio Marchini.
Application Number | 20140374008 14/365366 |
Document ID | / |
Family ID | 45540969 |
Filed Date | 2014-12-25 |
United States Patent
Application |
20140374008 |
Kind Code |
A1 |
Marchini; Maurizio ; et
al. |
December 25, 2014 |
Process and Apparatus for Manufacturing Tyres for Vehicle
Wheels
Abstract
Building the carcass structure of tyres for vehicle wheels
includes associating, at each end edge of a carcass ply, at least
one respective annular reinforcement structure formed by depositing
along a circumferential direction a plurality of reinforcement
elements having a first length. Such elements are cut to size from
a reinforced continuous band-like element fed to a cutting group
arranged at a first operative position adapted to allow a
barycentric grip of the reinforcement elements. The cutting group
can translate along a feeding direction of the band-like element to
a second operative position for cutting to size a plurality of
second reinforcement elements having a second length different from
the first length. The second operative position is defined on the
basis of the second length, so as to have a barycentric grip of the
second reinforcement elements too.
Inventors: |
Marchini; Maurizio; (Milano,
IT) ; Ballabio; Michele; (Milano, IT) ; De
Col; Christian; (Sedico (Belluno), IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PIRELLI TYRE S.P.A. |
MILANO |
|
IT |
|
|
Assignee: |
PIRELLI TYRE S.P.A.
MILANO
IT
|
Family ID: |
45540969 |
Appl. No.: |
14/365366 |
Filed: |
December 20, 2012 |
PCT Filed: |
December 20, 2012 |
PCT NO: |
PCT/IB2012/057518 |
371 Date: |
June 13, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61580937 |
Dec 28, 2011 |
|
|
|
Current U.S.
Class: |
156/117 ;
156/397 |
Current CPC
Class: |
B29D 30/165 20130101;
B29D 30/305 20130101; B29D 2030/082 20130101; B29D 30/1657
20130101; B29D 30/3057 20130101; B29D 2030/3085 20130101; B29D
2030/3092 20130101; B29D 30/3042 20130101 |
Class at
Publication: |
156/117 ;
156/397 |
International
Class: |
B29D 30/30 20060101
B29D030/30 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2011 |
IT |
MI2011A002349 |
Claims
1-21. (canceled)
22. A process for manufacturing a tyre for vehicle wheels,
comprising associating at least one reinforcement structure with at
least one tyre component formed on a forming support, wherein
associating said at least one reinforcement structure comprises:
feeding a reinforced continuous band-like element at a cutting
group by moving said reinforced continuous band-like element along
a feeding direction with a first advancing step, said cutting group
being arranged along the feeding direction in a first operative
position; cutting to size the reinforced continuous band-like
element to form at least one first reinforcement element having a
first cutting length; depositing said at least one first
reinforcement element on a respective deposition area defined on a
respective component of a first tyre; translating the cutting group
along the feeding direction from said first operative position to a
second operative position; moving the reinforced continuous
band-like element along the feeding direction with a second
advancing step different from the first advancing step; cutting to
size the reinforced continuous band-like element to form at least
one second reinforcement element having at least one second cutting
length different from said first cutting length; and depositing
said at least one second reinforcement element on a respective
deposition area defined on a respective component of a second tyre,
wherein said second operative position is defined on a basis of
said at least one second cutting length.
23. The process according to claim 22, wherein said second
operative position is far from said first operative position by a
distance, an extension of which along the feeding direction, is
defined on the basis of a difference between said at least one
second cutting length and said first cutting length.
24. The process according to claim 23, wherein said extension is
equal, in absolute value, to half a difference between said at
least one second cutting length and said first cutting length.
25. The process according to claim 22, wherein translating the
cutting group comprises: moving the cutting group along the feeding
direction away from or toward a barycentre of said at least one
first reinforcement element, respectively, depending on whether
said at least one second cutting length is greater or smaller than
said first cutting length, respectively,
26. The process according to claim 22, wherein depositing said at
least one first reinforcement element comprises: moving said at
least one first reinforcement element from the cutting group toward
the forming support; and positioning said at least one first
reinforcement element on a respective deposition area.
27. The process according to claim 26, wherein moving said at least
one first reinforcement element comprises: picking said at least
one first reinforcement element up from the cutting group through a
gripping member and moving said at least one first reinforcement
element up to a transfer position of said at least one first
reinforcement element to a positioning member.
28. The process according to claim 27, wherein positioning said at
least one first reinforcement element comprises: bringing, through
the positioning member, said at least one first reinforcement
element up to a deposition position defined at the forming support;
and depositing said at least one first reinforcement element on a
respective deposition area.
29. The process according to claim 26, wherein depositing said at
least one second reinforcement element comprises: moving said at
least one second reinforcement element from the cutting group
toward the forming support; and positioning said at least one
second reinforcement element on a respective deposition area.
30. The process according to claim 29, wherein depositing said at
least one first reinforcement element comprises: moving said at
least one first reinforcement element from the cutting group toward
the forming support; and positioning said at least one first
reinforcement element on a respective deposition area; wherein
moving said at least one first reinforcement element comprises:
picking said at least one first reinforcement element up from the
cutting group through a gripping member and moving said at least
one reinforcement element up to a transfer position of said at
least one first reinforcement element to a positioning member; and
wherein moving said at least one second reinforcement element from
the cutting group toward the forming support comprises: picking
said at least one second reinforcement element up from the cutting
group through said gripping member and moving said at least one
second reinforcement element up to said transfer position to said
positioning member.
31. The process according to claim 30, wherein positioning said at
least one first reinforcement element comprises: bringing, through
the positioning member, said at least one first reinforcement
element up to a deposition position defined at the forming support;
and depositing said at least one first reinforcement element on a
respective deposition area; and wherein positioning said at least
one second reinforcement element comprises: bringing, through the
positioning member, said at least one second reinforcement element
up to said deposition position defined at the forming support; and
depositing said at least one second reinforcement element on a
respective deposition area.
32. The process according to claim 30, wherein picking said at
least one first reinforcement element and at least one second
reinforcement element up from the cutting group through said
gripping member comprises: positioning said gripping member at a
barycentric position of said first reinforcement element and second
reinforcement element; and holding a respective reinforcement
element in said barycentric position.
33. The process according to claim 32, wherein transfer of each
reinforcement element from the gripping member to the positioning
member is carried out at the barycentric position of said
reinforcement element.
34. The process according to claim 22, wherein said at least one
tyre component is at least one carcass ply.
35. The process according to claim 34, wherein said respective
deposition area is defined on an end edge of said at least one
carcass ply.
36. An apparatus for building at least one reinforcement structure
on a tyre component formed on a forming support, comprising: a
device for feeding a reinforced continuous band-like element along
a feeding direction; a cutting group of the reinforced continuous
band-like element to form at least one first reinforcement element
and at least one second reinforcement element having a first
cutting length and at least one second cutting length that is
different from said first cutting length, respectively; at least
one moving and depositing device for moving said at least one first
reinforcement element and at least one second reinforcement element
close to the forming support and depositing said at least one first
reinforcement element and at least one second reinforcement element
on respective deposition areas defined on respective tyre
components; and a device for controlling the translation of said
cutting group along said feeding direction between a first
operative position defined on a basis of said first cutting length
and a second operative position defined on a basis of said at least
one second cutting length,
37. The apparatus according to claim 36, wherein the cutting group
is mounted on a support frame through an interposition of a sliding
rail extending along said feeding direction.
38. The apparatus according to claim 36, wherein said at least one
moving and depositing device comprises: at least one gripping
member of said at least one first reinforcement element and at
least one second reinforcement element, said at least one gripping
member being movable between the cutting group and a transfer
position.
39. The apparatus according to claim 38, wherein said at least one
moving and depositing device further comprises: at least one
positioning member which is movable between said transfer position
and a deposition position defined at the forming support.
40. The apparatus according to claim 38, comprising two positioning
members arranged on opposite sides with respect to a middle plane
of said apparatus,
41. The apparatus according to claim 36, wherein said forming
support is substantially cylindrical .
42. An apparatus for manufacturing tyres for vehicle wheels,
comprising an apparatus according to claim 36.
Description
[0001] The present invention relates to a process and an apparatus
for manufacturing tyres for vehicle wheels, in particular for
manufacturing tyres different from each other.
[0002] The present invention further relates to an apparatus for
manufacturing at least one reinforcement structure on a tyre
component formed on a forming support, such apparatus being usable
for manufacturing tyres for vehicle wheels, in particular tyres
different from each other.
[0003] A tyre for vehicle wheels generally comprises a carcass
structure comprising at least one carcass ply formed of reinforcing
cords embedded in an elastomeric matrix. The carcass ply has end
edges respectively engaged with annular anchoring structures. The
latter are arranged in the areas of the tyre usually identified by
the name "beads" and each of them is normally formed by a
substantially circumferential annular insert on which at least one
filling insert is applied, in a radially outer position thereof.
Such annular inserts are commonly identified as "bead cores" and
have the task of keeping the tyre firmly fixed to the anchoring
seat specifically provided in the rim of the wheel, thus
preventing, in operation, the radially inner end edge of the tyre
coming out from such a seat.
[0004] At the beads specific reinforcing structures may be provided
having the function of improving the torque transmission to the
tyre.
[0005] In a radially outer position with respect to the carcass ply
a belt structure comprising one or more belt layers is associated,
said belt layers being arranged radially one on top of the other
and having textile or metallic reinforcing cords with crossed
orientation and/or an orientation substantially parallel to the
direction of circumferential extension of the tyre.
[0006] Between the carcass structure and the belt structure a layer
of elastomeric material, known as "under-belt", can be provided,
said layer having the function of making the radially outer surface
of the carcass structure as uniform as possible for the subsequent
application of the belt structure.
[0007] In a radially outer position with respect to the belt
structure a tread band is applied, also made of elastomeric
material.
[0008] Between the tread band and the belt structure a so-called
"under-layer" of elastomeric material can be arranged, said
under-layer having properties suitable for ensuring a steady union
of the tread band itself.
[0009] On the side surfaces of the carcass structure respective
sidewalls of elastomeric material are also applied, each extending
from one of the side edges of the tread band up to the respective
annular anchoring structure to the beads.
[0010] The traditional processes for manufacturing tyres for
vehicle wheels essentially provide for the components of the tyre
listed above to be first made separately from one another, to be
then assembled on at least one building drum.
[0011] However, the current tendency is that of using manufacturing
processes that allow the manufacturing and storage of semi-finished
parts to be minimised or possibly eliminated.
[0012] Attention has now turned towards process solutions that
allow the individual components of the tyre to be made by directly
building them, according to a predetermined sequence, onto a
forming support, typically toroidal or cylindrical.
[0013] The term "reinforced continuous band-like element" is used
to indicate a continuous element comprising one or more thread-like
reinforcing elements, such as textile or metal cords, substantially
parallel to one another and embedded in a matrix of elastomeric
material or coated with a layer of elastomeric material.
[0014] Preferably, such reinforcing cords extend parallel to each
other along the direction of longitudinal extension of the same
reinforced continuous band-like element.
[0015] A cutting to size of said reinforced continuous band-like
element, fed along a feeding direction, generates a "reinforcing
element".
[0016] "Cutting length" is defined as the measure of said
reinforcement element along said feeding direction of the
reinforced continuous band-like element.
[0017] The term: "elastomeric material" is used to indicate a
composition comprising at least one elastomeric polymer and at
least one reinforcing filler. Preferably, such a composition
further comprises additives such as, for example, a cross-linking
agent and/or a plasticizer. Thanks to the provision of the
cross-linking agent, such material may be cross linked by heating,
so as to make the end product.
[0018] The terms "radial" and "axial" and the expressions "radially
inner/outer" and "axially inner/outer" are used with reference to
the radial direction and to the axial direction of a forming
support used for building a specific tyre component. The terms
"circumferential" and "circumferentially" instead, are used
referring to the annular extension of the forming support.
[0019] The expression "tyre component" is used to indicate any
structural element of a tyre, or even just a portion of such
structural element, which is suitable for carrying out a specific
function when the tyre is used in a running vehicle. Such component
may be for example the liner, the under-liner, the abrasion-proof
element, the bead core, the bead filler, the carcass ply, the belt
strip, the under-belt layer, the under-layer of the tread band, the
sidewall inserts, the sidewalls, the tread band, the reinforcement
inserts, etc.
[0020] The expression "barycentric grip condition" and/or
"barycentric position" is used to indicate a condition and/or
position wherein the reinforcement element is gripped or held at a
surface portion thereof extending symmetrically on opposite sides
with respect to the barycentre of the reinforcement element.
[0021] EP 0 956 940 describes a process for manufacturing a
reinforcement layer in a tyre being formed on a forming support.
Such reinforcement layer is obtained by sequentially depositing a
plurality of reinforcement elements on the forming support, along a
circumferential direction of an outer peripheral surface thereof.
Such reinforcement elements are cut to size in a proper cutting
group from a reinforcement band-like element. Subsequent to the
cut, each reinforcement element is picked up by proper gripping
members and deposited on the outer peripheral surface of the
forming support.
[0022] WO 2010/067139 describes a process for manufacturing tyres
for vehicle wheels, wherein a reinforcement annular structure is
associated at each one of the axially opposite end edges of a
carcass ply deposited on a substantially cylindrical forming
support, such annular reinforcement structure being obtained by
deposition on the carcass ply of a plurality of reinforcement
elements cut to size from a reinforced continuous band-like element
fed in the proximity of the forming support. Each reinforcement
element, once cut to size, is picked up by a gripping member for
the subsequent deposition on the carcass ply. In particular, in a
preferred embodiment, the gripping member transfers the
reinforcement element to a positioning member which in turn
deposits it on the respective end edge of the carcass ply.
[0023] The Applicant has found that in the processes of the type
described in WO 2010/067139, in order to ensure an accurate and
repeatable deposition of all the reinforcement elements on a tyre
component (for example on the end edges of the carcass ply)
deposited on a forming support, it is preferable setting the
apparatus so that the pickup of the reinforcement element from the
cutting group by the gripping member and the transfer of the
reinforcement element from the gripping member to the positioning
member takes place at respective barycentric positions of the
individual reinforcement elements.
[0024] However, the Applicant has noted that since the above pickup
and transfer positions are fixed in the space once the tyre
manufacturing apparatus has been set, whenever it is necessary to
change the cutting length of the reinforcement element (such as for
manufacturing a batch of tyres having a different fitting diameter
and/or a number of reinforcement elements other than that of the
previously manufactured batch of tyres), it is necessary to first
provide for a new set up of the apparatus. This is because,
otherwise, the pickup of the reinforcement element from the cutting
group by the gripping member and the transfer of the same
reinforcement element from the gripping member to the positioning
member would not take place at respective barycentric positions of
the individual reinforcement elements.
[0025] The Applicant has observed that the above working conditions
do not ensure a deposition of the reinforcement elements on a tyre
component (for example on the end edges of the carcass ply)
according to the project design; this would imply repeated manual
corrections of the apparatus setup at each variation of the
reinforcement element geometry.
[0026] Since such setup requires the accurate adjustment of the
relative positions between the gripping member and the positioning
member, it is quite burdensome in terms of labour cost and
manufacturing time.
[0027] The Applicant has therefore perceived the need of
simplifying the apparatus setup operation as much as possible
whenever it is necessary to change the cutting length of the
reinforcement elements, ensuring at the same time that such
simplification does not impair the correct positioning of the
reinforcement elements on the tyre component (for example on the
end edge of the carcass ply) deposited on the forming support.
[0028] To this end, the Applicant has perceived that, upon
variation of the cutting length of the reinforcement elements, it
is possible to obtain an accurate and repeatable deposition
condition of the reinforcement elements by intervening in the setup
step on only one of the apparatus devices and/or members, and in
particular on the cutting group only.
[0029] Finally, the Applicant has found that by translating each
time the cutting group along the feeding direction of the
reinforced continuous band-like element by a length which is
variable on the basis of the extent of the cutting length variation
each time required, it is possible to always ensure the desired
barycentric grip condition of the reinforcement elements by the
gripping member at the cutting group. More in detail, the desired
barycentric position of the reinforcement element is kept also when
the reinforcement element is transferred from the gripping member
to the positioning member, thus obtaining an accurate and
repeatable deposition of the reinforcement elements on the tyre
component (for example on the end edge of the carcass ply)
deposited on the forming support.
[0030] More in particular, the Applicant has found that once the
cutting group has been positioned along the feeding direction of
the reinforced continuous band-like element at a first operative
position defined according to a first cutting length of the
reinforcement elements, when it is desired to switch to a second
cutting length different from the first cutting length it is
possible to keep the desired barycentric grip condition of the
reinforcement elements by translating the cutting group along the
above feeding direction up to a second operative position defined
on the basis of the above second cutting length.
[0031] Therefore, in a first aspect thereof, the present invention
relates to a process for manufacturing tyres for vehicle wheels,
comprising associating at least one reinforcement structure with at
least one tyre component formed on a forming support. Associating
said at least one reinforcement structure comprises at least one of
the following actions: [0032] feeding a reinforced continuous
band-like element at a cutting group by moving it along a feeding
direction with a first advancing step, said cutting group being
arranged along the feeding direction in a first operative position;
[0033] cutting to size the reinforced continuous band-like element
to form at least one first reinforcement element having a first
cutting length; [0034] depositing said at least one first
reinforcement element on a respective deposition area defined on a
respective component of a first tyre; [0035] translating the
cutting group along the feeding direction from said first operative
position to a second operative position; [0036] moving the
reinforced continuous band-like element along the feeding direction
with a second advancing step different from the first advancing
step; [0037] cutting to size, the reinforced continuous band-like
element to form at least one second reinforcement element having at
least one second cutting length different from said first cutting
length; [0038] depositing said at least one second reinforcement
element on a respective deposition area defined on a respective
component of a second tyre;
[0039] wherein said second operative position is defined on the
basis of said at least one second cutting length.
[0040] The Applicant believes that since the process of the present
invention provides for a gripping condition of the reinforcement
elements in a barycentric position, it advantageously allows, in a
very simple and effective manner (thus without any burden in terms
of labour cost and manufacturing time) an accurate and repeatable
deposition condition on the tyre component to be maintained as the
cutting length of the above reinforcement elements changes.
[0041] In a second aspect thereof, the present invention relates to
an apparatus for building at least one reinforcement structure on a
tyre component formed on a forming support.
[0042] Said apparatus may comprise: [0043] a device for feeding a
reinforced continuous band-like element along a feeding direction;
[0044] a cutting group of the reinforced continuous band-like
element to form at least one first reinforcement element and at
least one second reinforcement element having a first cutting
length and at least one second cutting length that is different
from said first cutting length, respectively; [0045] at least one
moving and depositing device for moving said at least one first
reinforcement element and at least one second reinforcement element
close to the forming support and depositing said at least one first
reinforcement element and at least one second reinforcement element
on respective deposition areas defined on respective tyre
components; [0046] a device for controlling the translation of said
cutting group along said feeding direction between a first
operative position defined on the basis of said first cutting
length and a second operative position defined on the basis of said
at least one second cutting length.
[0047] In a third aspect thereof, the present invention relates to
an apparatus for manufacturing tyres for vehicle wheels comprising
an apparatus for building at least one reinforcement structure as
described above.
[0048] The present invention, in at least one of the above aspects
thereof, can comprise at least one of the following preferred
features.
[0049] Preferably, the second operative position is far from the
first operative position by a distance whose extension, along the
feeding direction, is defined on the basis of the difference
between said at least one second cutting length and said first
cutting length.
[0050] More preferably, said extension is equal, in absolute value,
to half the difference between said at least one second cutting
length and said first cutting length.
[0051] Even more preferably, translating the cutting group
comprises: [0052] moving the cutting group along the feeding
direction away from or towards the barycentre of said at least one
first reinforcement element, respectively, depending on whether
said at least one second cutting length is greater or smaller than
said first cutting length, respectively.
[0053] Advantageously, the above provisions allow the desired
barycentric grip of the reinforcement elements to always be
achieved irrespective of the extent of the required cutting length
variation.
[0054] In preferred embodiments of the present invention,
depositing said at least one first reinforcement element comprises:
[0055] moving said at least one first reinforcement element from
the cutting group towards the forming support; [0056] positioning
said at least one first reinforcement element on the respective
deposition area.
[0057] Advantageously, said positioning takes place always in the
desired circumferentially symmetrical position with respect to a
radial plane of the forming support.
[0058] Preferably, moving said at least one first reinforcement
element comprises: [0059] picking said at least one first
reinforcement element up from the cutting group through a gripping
member and moving it up to a transfer position of said at least one
first reinforcement element to a positioning member.
[0060] Preferably, positioning said at least one first
reinforcement element comprises: [0061] bringing, through the
positioning member, said at least one first reinforcement element
up to a deposition position defined at the forming support; [0062]
depositing said at least one first reinforcement element on the
respective deposition area.
[0063] In preferred embodiments of the present invention,
depositing said at least one second reinforcement element
comprises: [0064] moving said at least one second reinforcement
element from the cutting group towards the forming support; [0065]
positioning said at least one second reinforcement element on the
respective deposition area.
[0066] Preferably, moving said at least one second reinforcement
element from the cutting group towards the forming support
comprises: [0067] picking said at least one second reinforcement
element up from the cutting group through said gripping member and
moving it up to said transfer position to said positioning
member.
[0068] Preferably, positioning said at least one second
reinforcement element comprises: [0069] bringing, through the
positioning member, said at least one second reinforcement element
up to said deposition position defined at the forming support;
[0070] depositing said at least one second reinforcement element on
the respective deposition area.
[0071] Preferably, picking said at least one first reinforcement
element and at least one second reinforcement element up from the
cutting group through said gripping member comprises: [0072]
positioning said gripping member at a barycentric position of said
first reinforcement element and second reinforcement element;
[0073] holding the respective reinforcement element in said
barycentric position.
[0074] Preferably, the transfer of each reinforcement element from
the gripping member to the positioning member is carried out at the
barycentric position of said reinforcement element.
[0075] Preferably, said at least one tyre component is at least one
carcass ply.
[0076] Preferably, said respective deposition area is defined on an
end edge of said at least one carcass ply.
[0077] In preferred embodiments of the present invention, the
cutting group is mounted on a support frame through the
interposition of a sliding rail extending along said feeding
direction.
[0078] Such sliding rail advantageously allows the movement of the
cutting group in the most appropriate operative position on the
basis of the required cutting length.
[0079] Preferably, said at least one moving and depositing device
comprises: [0080] at least one gripping member of said at least one
first reinforcement element and at least one second reinforcement
element, said at least one gripping member being movable between
the cutting group and a transfer position.
[0081] Preferably, said at least one moving and depositing device
further comprises: [0082] at least one positioning member which is
movable between said transfer position and a deposition position
defined at the forming support.
[0083] In preferred embodiments thereof, the apparatus comprises
two positioning members arranged on opposite sides with respect to
a middle plane of said apparatus.
[0084] Advantageously, the middle plane of the apparatus of the
present invention corresponds to an axial symmetry plane of the
tyre being formed, i.e. to the equatorial plane of the tyre.
[0085] Preferably, the forming support is substantially
cylindrical.
[0086] Further features and advantages of the present invention
will appear more clearly from the following detailed description of
some preferred embodiments of an apparatus and process according to
the present invention, made with reference to the annexed drawings.
In such drawings:
[0087] FIG. 1 is a simplified schematic plan view of an apparatus
for manufacturing tyres for vehicle wheels according to the present
invention, in an operative configuration thereof;
[0088] FIG. 2a is a simplified schematic plan view of a cutting
group of the apparatus of FIG. 1 in a first working position
thereof;
[0089] FIG. 2b is a simplified schematic plan view of the cutting
group of the apparatus of FIG. 1 in a second working position
thereof;
[0090] FIG. 3 is a simplified schematic plan view of a gripping
member of the apparatus of FIG. 1 in a gripping position of
reinforcement elements having different cutting lengths;
[0091] FIG. 4 is a simplified schematic plan view of the gripping
member and of a positioning member of the apparatus of FIG. 1 in a
transfer position of reinforcement elements having a different
cutting lengths from the gripping member to the positioning
member;
[0092] FIG. 5 is a simplified schematic plan view of the
positioning member of the apparatus of FIG. 1 in a deposition
position of reinforcement elements having a different cutting
lengths on a forming support.
[0093] In FIG. 1, reference numeral 100 globally indicates an
exemplary embodiment of an apparatus for manufacturing tyres for
vehicle wheels according to the present invention.
[0094] Preferably, apparatus 100 may be used in a process for
manufacturing different batches of tyres.
[0095] More preferably, apparatus 100 allows associating respective
reinforcement structures to specific tyre components.
[0096] In the specific embodiment illustrated herein, apparatus 100
is used for building carcass structures. Such building in
particular comprises forming a first annular reinforcement
structure 1a, 1b at each end edge 2a, 2b of a first carcass ply 2
deposited on a forming support 150 for manufacturing a first batch
of tyres, and forming an annular reinforcement structure 1a, 1b at
each end edge 2a, 2b of a second carcass ply 2' deposited on the
forming support 150, for manufacturing a second batch of tyres
differing from the tyres of the first batch at least by the width
of the reinforcement structure and/or the deposition angle of the
reinforcement element on the end edge of the carcass ply.
Preferably, the forming support 150 is cylindrical.
[0097] The above end edges 2a, 2b are defined at axial end zones of
the carcass ply 2, 2' configured to define the bead region of the
tyres.
[0098] Throughout the present description, reference shall first be
made to the building of the reinforcement structures 1a, 1b on a
first carcass ply 2 for manufacturing the first batch of tyres.
[0099] Each reinforcement structure 1a, 1b extends in a
circumferential direction on the respective end edge 2a, 2b of the
carcass ply 2 and is defined by a predetermined number of
reinforcement elements 5a, 5b, having the same length L1 and width
W, deposited one after the other on respective deposition areas
defined on the opposite end edges 2a, 2b of the carcass ply 2.
[0100] In particular, FIG. 1 shows a reinforcement structure 1a
being formed through deposition of the reinforcement elements 5a at
the end edge 2a of the carcass ply 2 and a reinforcement structure
1b being formed through deposition of the reinforcement elements 5b
at the opposite end edge 2b of the carcass ply 2.
[0101] Apparatus 100 comprises a support frame 101 whereto, in
operation, the forming support 150 is moved close and on which the
various members or devices needed for forming the reinforcement
structures 1a, 1b are mounted.
[0102] In order to allow the subsequent deposition in
circumferential direction of the reinforcement elements 5a, 5b, the
forming support 150 is periodically controlled in rotation about
the axis of rotation X-X thereof by an angle corresponding to a
predetermined circumferential step.
[0103] The reinforcement elements 5a, 5b are preferably obtained by
operations of cutting to size at least one reinforced continuous
band-like element 4 extending along a direction of longitudinal
extension, indicated with letter G in FIG. 1, and fed close to the
forming support 150 through a proper feeding device 20.
[0104] The reinforced continuous band-like element 4 has a defined
and constant width W, preferably comprised between 1 and 100 mm,
more preferably between 30 and 70 mm.
[0105] The reinforced continuous band-like element 4 is fed along
the direction G of longitudinal extension thereof by the feeding
device 20 with a predetermined advancing step, such step defining a
predetermined cutting length L1 of the reinforced continuous
band-like element 4, which corresponds to a predetermined width of
the reinforcement elements 5a, 5b when they are deposited on the
forming support 150.
[0106] The expressions "direction of longitudinal extension" and
"feeding direction" shall be used without distinction to refer to
the same direction indicated with letter G in FIG. 1.
[0107] Apparatus 100 comprises a cutting group 30 configured to
carry out the sequential operations of cutting to size the
reinforced continuous band-like element 4 for obtaining the
reinforcing elements 5a, 5b in a sequence.
[0108] The cutting group 30 acts on the continuous reinforced
band-like element 4, with a predetermined cutting frequency, along
a cutting direction defining, on the lying plane of the reinforced
continuous band-like element 4, a predetermined cutting angle
.alpha. with the direction G of longitudinal extension of the
reinforced continuous band-like element 4.
[0109] In the preferred embodiments of the present invention, the
cutting angle .alpha. is set to a value greater than zero,
preferably comprised between about 15.degree. and about 90.degree.,
more preferably between about 20.degree. and about 50.degree., even
more preferably between about 22.degree. and about 45.degree..
[0110] If the cutting angle .alpha. is equal to 90.degree., length
L1 of the reinforcement elements 5a, 5b deposited on the forming
support 150 corresponds to width W of the reinforced continuous
band-like element 4. If the cutting angle .alpha. is smaller than
90.degree., length L1 of the reinforcement elements 5a, 5b is equal
to width W of the reinforced continuous band-like element 4 divided
by the sine of angle .alpha..
[0111] The cutting group 30 is pivoted to frame 101 about a
respective axis of rotation and can rotate as a whole around such
axis for allowing the cutting of the reinforced continuous
band-like element 4 with different angles .alpha..
[0112] As shown in FIGS. 1 and 2a, the cutting group 30 is mounted
on a pair of sliding rails 31 associated with support frame 101 and
extending parallel to the feeding direction G of the reinforced
continuous band-like element 4. In this way, the cutting group 30
can translate along the feeding direction G of the reinforced
continuous band-like element 4 for positioning at operative
positions different from that shown in FIG. 1, thus allowing the
cut of reinforcement elements having lengths different from that of
the reinforcement elements 5a, 5b.
[0113] As shall appear more clearly throughout the present
description, the different operative positions of the cutting group
30 are defined on the basis of the desired cutting length of the
reinforcement elements.
[0114] In order to control the translation of the cutting group 30
(indicated with double arrow A in FIG. 1) along the feeding
direction G, apparatus 100 comprises a proper control device 35
associated with the cutting group 30.
[0115] Downstream of the cutting group 30, i.e. between the cutting
group 30 and the forming support 150, a moving and depositing
device of the reinforcement elements 5a, 5b is provided.
[0116] The moving and depositing device in particular comprises a
gripping member 40 of the reinforcement elements 5a, 5b.
[0117] The gripping member 40 comprises a pair of arms 41a, 41b
configured to alternately pick the reinforcement element 5a, 5b
just made up to move it towards the respective end edge 2a, 2b of
the carcass ply 2 deposited on the forming support 150.
[0118] Arms 41a, 41b are fixedly connected to one another and
angularly spaced by a predetermined angle, preferably equal to
90.degree..
[0119] Each arm 41a, 41b comprises, at a free end thereof, a clamp
42a, 42b for gripping the reinforcement element 5a, 5b to be
cut.
[0120] Each clamp 42a, 42b is slidingly mounted on the respective
arm 41a, 42b so as to carry out a linear sliding movement with
respect to arms 41a, 41b along the respective longitudinal
directions. Such movement allows the release of the reinforcement
element 5a, 5b just cut from the cutting group 30 for the
subsequent movement thereof towards the forming support 150.
[0121] The grip of the reinforcement elements 5a, 5b by clamps 42a,
42b takes place at barycentre B of the above reinforcement elements
(i.e. at a barycentric position), as schematically shown in FIGS.
2a and 3.
[0122] The gripping member 40 is pivoted to frame 101 around a
respective axis of rotation Y.sub.1 defined at a plane M of
apparatus 100, such plane M corresponding to the equatorial plane
of the tyre being formed on the forming support 150.
[0123] The gripping member 40 can rotate about axis Y.sub.1 in both
directions of rotation with an alternating movement, so as to move
in an alternating sequence the reinforcement elements 5a towards
the end edge 2a of the carcass ply 2 and the reinforcement elements
5b towards the end edge 2b of the carcass ply 2.
[0124] The moving and depositing device further comprises, between
the gripping member 40 and the forming support 150, a pair of
positioning members 50a, 50b, each configured for picking a
respective reinforcement element 5a, 5b up from a respective arm
41a, 41b of the gripping member 40 at a respective transfer
position after such arm has made a predetermined angular movement
(preferably equal to 90.degree.) starting from the cutting group
30.
[0125] The positioning members 50a, 50b (which are absolutely
identical to one another) are preferably arranged symmetrically on
the opposite sides with respect to plane M of apparatus 100 and are
moved synchronously with arms 41a, 41b. Each reinforcement element
5a, 5b can thus be transferred by a respective arm 41a, 41b of the
gripping member 40. to a respective positioning member 50a, 50b,
which then deposits the reinforcement element 5a, 5b on a
respective end edge 2a, 2b of the carcass ply 2 deposited on the
forming support 150.
[0126] Each positioning member 50a, 50b comprises a respective
articulated arm in turn comprising a first arm 51a, 51b having a
free end pivoted on frame 101 at a pivoting axis Y.sub.2, and a
second arm 52a, 52b having a free end pivoted at a pivoting axis
Y.sub.3 on a free end of the respective first arm 51a, 52a opposite
the one where the respective first arm 51a, 52a is pivoted to frame
101.
[0127] Each second arm 52a, 52b comprises, at a free end thereof
opposite the one where the second arm 52a, 52b is pivoted to the
first arm 51a, 51b, a respective support member 53a, 53b configured
to pick the respective reinforcement element 5a, 5b up from the
respective arm 41a, 41b of the gripping member 40 at the above
transfer position for moving it to the respective end edge 2a, 2b
of the carcass ply 2 deposited on the forming support 150.
[0128] The transfer of the reinforcement element 5a, 5b from arm
41a, 41b of the gripping member 40 to the support member 53a, 53b
of the positioning member 50a, 50b takes place so that the
reinforcement element 5a, 5b is subsequently held by the respective
support member 53a, 53b at barycentre B thereof, i.e. at a
barycentric position.
[0129] Each support member 53a, 53b is provided with a device for
holding the reinforcement element 5a, 5b by suction or suction cup
or electromagnet (according to whether the reinforcement cords
inside the reinforcement elements are textile or metal), configured
to prevent the reinforcement element 5a, 5b from falling down
during the movement towards the forming support 150.
[0130] Each support member 53a, 53b is movable parallel to the
pivoting axes Y.sub.2 and Y.sub.3 for allowing the deposition of
the reinforcement elements 5a, 5b on the end edges 2a, 2b of the
carcass ply 2 deposited on the forming support 150.
[0131] In a preferred embodiment of apparatus 100 of the present
invention, such as that illustrated herein, the support members
53a, 53b, after having deposited the reinforcement elements 5a, 5b
on the respective end edges 2a, 2b of the carcass ply 2, press such
reinforcement elements 5a, 5b against the forming support 150 so as
to deform them consistently with the geometry of the forming
support 150, thus achieving the complete laying of the
reinforcement elements 5a, 5b on the above end edges 2a, 2b.
[0132] In an alternative embodiment of apparatus 100 of the present
invention, not shown, a pair of respective pressing members
configured to press on the reinforcement elements 5a, 5b after they
have been deposited by the support members 53a, 53b on the above
end edges 2a, 2b are provided downstream of the positioning members
50a, 50b, i.e. between the positioning members 50a, 50b and the
forming support 150.
[0133] Irrespective of the specific embodiment of apparatus 100
being used, the reinforcement elements 5a, 5b are each time
deposited on the end edges 2a, 2b at respective deposition areas
defined in circumferentially symmetrical positions with respect to
a vertical radial plane of the forming support 150, that is so that
barycentre B of the reinforcement element 5a, 5b deposited is on
said radial plane, as shown in FIG. 5.
[0134] Apparatus 100 may further comprise a pair of idle rollers
(not shown in the figures) movable perpendicularly to the rotation
axis X-X of the forming support 150. Such rollers are coated with a
deformable material and are arranged at opposite sides with respect
to plane M of apparatus 100, each one in the proximity of a
respective positioning member 50a, 50b.
[0135] The above rollers are configured to be activated when the
respective reinforcement structure 1a, 1b has been completed at
each end edge 2a, 2b of the carcass ply 2 for improving the
compaction and adhesion of said reinforcement structure 1a, 1b on
the carcass ply 2.
[0136] With reference to FIG. 1, a preferred embodiment of the
process carried out by apparatus 100 described above shall now be
described, aimed to the manufacture of a first batch of tyres
wherein the reinforcement structures 1a, 1b comprise reinforcement
elements 5a, 5b having a predetermined first length L1.
[0137] Before starting the above process, a carcass ply 2 is
deposited on the forming support 150 and the forming support 150 is
moved close to frame 101. Apparatus 100 is then set up on the basis
of the features of the tyres to be made.
[0138] The setup of apparatus 100 comprises, among the other
things, the positioning of the cutting group 30 at the desired
cutting angle .alpha. with respect to the feeding direction G of
the reinforced continuous band-like element 4. The above setup
further comprises the positioning of the cutting group 30 in an
operative position defined along the feeding direction G of the
reinforced continuous band-like element 4 on the basis of the
desired cutting length L1.
[0139] As described above, in the above process the reinforcement
elements 5a, 5b are cut in a sequence from the reinforced
continuous band-like element 4 and they are alternately deposited
each on a respective end edge 2a, 2b of the carcass ply 2. In
particular, the deposition of a reinforcement element 5a on an end
edge 2a takes place immediately after a reinforcement element 5b
has been deposited on the other end edge 2b and vice versa, so as
to make a reinforcement structure 1a on the end edge 2a while
another reinforcement structure 1b is made on the end edge 2b.
[0140] At the regime state, thus, there is a situation wherein at
least one reinforcement element 5a has already been deposited on
the end edge 2a and at least one reinforcement element 5b has
already been deposited on the other end edge 2b. Such situation is
shown in FIG. 1.
[0141] Starting from such situation, the reinforced continuous
band-like element 4 is moved along said feeding direction G by a
predetermined advancing step. During advancing of the reinforced
continuous band-like element 4, gripping member 40 is made to
rotate so as to bring arm 41a at the cutting group 30. In this
position, arm 41a is activated to pick a free end of the reinforced
continuous band-like element 4 up.
[0142] Simultaneously with the rotation of the gripping member 40,
a synchronous rotation of the positioning member 50a takes
place.
[0143] Afterwards, the reinforced continuous band-like element 4 is
cut to obtain the reinforcement element 5a.
[0144] FIG. 1 shows an operative configuration of the apparatus and
process of the present invention wherein the reinforcement element
5b just cut has been picked up by clamp 42b of arm 41b of the
gripping member 40 and the latter has been moved by about
90.degree. to bring clamp 42b to a transfer position of the
reinforcement element 5b to the positioning member 50b which
meanwhile has been moved towards the gripping member 40. At the
same period of time, arm 41a of the gripping member 40 has been
brought at the cutting group 30 for picking up the reinforcement
element 5a which is about to be cut from the reinforced continuous
band-like element 4.
[0145] After the reinforcement element 5b has been transferred from
the gripping member 40 to the positioning member 50b, the latter is
made to rotate about the pivoting axis Y.sub.2 to bring the above
reinforcement element 5b at the end edge 2b of the carcass ply 2.
During such rotation, the reinforcement element 5b is held at the
barycentric position on the support member 53b of the positioning
member 50b by the holding device described above.
[0146] Meanwhile, the forming support 150 is made to rotate about
axis X-X by a predetermined angle corresponding to a movement in
the circumferential direction by a length equal to (if the
circumferentially consecutive reinforcement elements 5a, 5b must be
deposited in contact with each other and without overlapping) or
greater than (if the reinforcement elements 5a, 5b must be
deposited leaving a free space between two circumferentially
consecutive reinforcement elements) the advancing step of the
reinforced continuous band-like element 4.
[0147] Once the support member 53b is at a radially outer position
with respect to the forming support 150, the support member 53b is
moved towards the forming support 150 (and thus in a direction
perpendicular to the rotation axis X-X of the forming support 150)
up to positioning the reinforcement element 5b on a respective
deposition area defined on the end edge 2b of the carcass ply
2.
[0148] Subsequently, the support member 53b exerts a predetermined
thrust action against the forming support 150, so as to obtain the
complete laying of the reinforcement element 5b on the end edge 2b
of the carcass ply 2.
[0149] As an alternative, said thrust action may be carried out by
a pressing member separate from the support member 53b.
[0150] The process described above is repeated cyclically through
the positioning members 50a and 50b, each time depositing a new
reinforcement element 5a, 5b on the respective end edge 2a, 2b of
the carcass ply 2, up to completing the reinforcement structures
1a, 1b on both end edges 2a, 2b of the carcass ply 2.
[0151] Afterwards, if the idle rollers described above are
provided, each one of such idle rollers is brought in contact with
the respective reinforcement structure 1a, 1b just formed. The
rotation of the forming support 150 is then controlled for at least
one full revolution. The action of the rollers during such rotation
produces the compaction of the reinforcement structures 1a, 1b on
the respective end edges 2a, 2b of the carcass ply 2.
[0152] According to the present invention, a process totally
similar to that described above may be carried out by the same
apparatus 10.0 for manufacturing a second batch of tyres differing
from the tyres of the first batch in that the reinforcement
structures 1a, 1b of the tyres of the second batch comprise
reinforcement elements 15a, 15b having a cutting length L2
different from the cutting length of the reinforcement elements 5a,
5b of the tyres of the first batch.
[0153] Throughout the present description, particular reference is
made to the case where length L2 is lower than length L1, as shown
in FIG. 2b.
[0154] In this case, a carcass ply 2' is deposited on the forming
support 150 and the process described above is repeated.
[0155] In particular, in order to proceed with the cutting of the
reinforcement elements 15a, 15b to the desired length L2, the
cutting group 30 is first translated along the feeding direction G
of the reinforced continuous band-like element 4 towards barycentre
B of the reinforcement elements 5a, 5b previously cut (i.e. in the
direction indicated by arrow T in FIG. 2a). In particular, the
cutting group 30 is moved from a first operative position taken for
cutting the reinforcement elements 5a, 5b having length L1 to a new
operative position which is far from the first operative position
by a distance P whose longitudinal extension along the feeding
direction G is a function of the difference between length L1 and
length L2 (FIGS. 2a and 2b).
[0156] More in particular, said extension is equal to half the
difference between length L1 and length L2.
[0157] Of course, if length L2 is greater than length L1, the
movement of the cutting group 30 takes place in a direction
opposite to that indicated with letter T in FIG. 2 (i.e. away from
barycentre B of the reinforcement elements 5a, 5b previously cut)
and the extent of distance P is equal to half the difference
between length L2 and length L1.
[0158] In this way, it is ensured that the pickup of the
reinforcement elements 15a, 15b by clamps 42a, 42b of the gripping
member 40 and the transfer of the same to the support members 53a,
53b of the positioning members 50a, 50b always takes place at a
barycentric position, as described above with reference to the
reinforcement elements 5a, 5b (FIG. 4).
[0159] Accordingly, it is ensured that the deposition of the
reinforcement elements 15a, 15b on the end edges 2a, 2b of the
carcass ply 2' each time takes place at circumferentially
symmetrical positions with respect to the vertical radial plane of
the forming support 150, as described above with reference to the
reinforcement elements 5a, 5b (FIG. 5).
[0160] In other words, as shown in FIGS. 3-5, during all the
process steps of the present invention the spatial position of
barycentre B of the reinforcement elements 15a, 15b always matches
that of barycentre B of the reinforcement elements 5a, 5b.
[0161] In this way, it is possible to ensure the accurate and
repeatable deposition of the reinforcement elements 5a, 5b, 15a,
15b on the end edges 2a, 2b of the carcass plies 2, 2' upon the
variation of the cutting length of the reinforcement elements.
[0162] Of course, a man skilled in the art can make further
modifications and variants to the invention described above in
order to satisfy specific and contingent application requirements,
these variants and modifications in any case being within the scope
of protection as defined by the following claims.
* * * * *